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Filename Latest commit message Latest commit date
Alexander Shishkin 8a58ddae23 perf/core: Fix exclusive events' grouping
So far, we tried to disallow grouping exclusive events for the fear of
complications they would cause with moving between contexts. Specifically,
moving a software group to a hardware context would violate the exclusivity
rules if both groups contain matching exclusive events.

This attempt was, however, unsuccessful: the check that we have in the
perf_event_open() syscall is both wrong (looks at wrong PMU) and
insufficient (group leader may still be exclusive), as can be illustrated
by running:

  $ perf record -e '{intel_pt//,cycles}' uname
  $ perf record -e '{cycles,intel_pt//}' uname

ultimately successfully.

Furthermore, we are completely free to trigger the exclusivity violation
by:

   perf -e '{cycles,intel_pt//}' -e '{intel_pt//,instructions}'

even though the helpful perf record will not allow that, the ABI will.

The warning later in the perf_event_open() path will also not trigger, because
it's also wrong.

Fix all this by validating the original group before moving, getting rid
of broken safeguards and placing a useful one to perf_install_in_context().

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: mathieu.poirier@linaro.org
Cc: will.deacon@arm.com
Fixes: bed5b25ad9 ("perf: Add a pmu capability for "exclusive" events")
Link: https://lkml.kernel.org/r/20190701110755.24646-1-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-13 11:21:28 +02:00
arch perf/x86/amd/uncore: Set the thread mask for F17h L3 PMCs 2019-07-13 11:21:27 +02:00
block for-5.3/block-20190708 2019-07-09 10:45:06 -07:00
certs Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
crypto USB / PHY patches for 5.3-rc1 2019-07-11 15:40:06 -07:00
Documentation Driver Core and debugfs changes for 5.3-rc1 2019-07-12 12:24:03 -07:00
drivers Driver Core and debugfs changes for 5.3-rc1 2019-07-12 12:24:03 -07:00
fs Driver Core and debugfs changes for 5.3-rc1 2019-07-12 12:24:03 -07:00
include perf/core: Fix exclusive events' grouping 2019-07-13 11:21:28 +02:00
init mm: init: report memory auto-initialization features at boot time 2019-07-12 11:05:46 -07:00
ipc treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
kernel perf/core: Fix exclusive events' grouping 2019-07-13 11:21:28 +02:00
lib Driver Core and debugfs changes for 5.3-rc1 2019-07-12 12:24:03 -07:00
LICENSES
mm Driver Core and debugfs changes for 5.3-rc1 2019-07-12 12:24:03 -07:00
net Driver Core and debugfs changes for 5.3-rc1 2019-07-12 12:24:03 -07:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2019-07-11 10:55:49 -07:00
scripts Driver Core and debugfs changes for 5.3-rc1 2019-07-12 12:24:03 -07:00
security Merge branch 'akpm' (patches from Andrew) 2019-07-12 11:40:28 -07:00
sound Driver Core and debugfs changes for 5.3-rc1 2019-07-12 12:24:03 -07:00
tools perf/core improvements and fixes: 2019-07-13 11:12:47 +02:00
usr
virt arm64: switch to generic version of pte allocation 2019-07-12 11:05:45 -07:00
.clang-format
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes
.gitignore .gitignore: exclude .get_maintainer.ignore and .gitattributes 2019-05-18 11:49:54 +09:00
.mailmap MAINTAINERS: Update my email address 2019-06-18 14:37:27 +01:00
COPYING
CREDITS Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2019-06-25 01:32:59 +02:00
Kbuild
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS Merge branch 'akpm' (patches from Andrew) 2019-07-12 11:40:28 -07:00
Makefile Linux 5.2 2019-07-07 15:41:56 -07:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.